Here is the Wikipaedia entry.  Any thoughts?

Improvisation is the process of devising a solution to a requirement by making-do, despite absence of resources that might be expected to produce a solution. In a technical context, this can mean adapting a device for some use other than that which it was designed for, or building a device from unusual components in an ad-hoc fashion. Improvisation in the context of performing arts is spontaneous performance without specific preparation. Improvisation can be thought of as an “on the spot” or “off the cuff” spontaneous moment of sudden inventiveness that can just come to mind, body and spirit as an inspiration. The skills of improvisation can apply to many different abilities or forms of communication and expression across all artistic, scientific, physical, cognitive, academic, and non-academic disciplines. For example, improvisation can make a significant contribution in music, dance, cooking, presenting a speech, sales, personal or romantic relationships, sports, flower arranging, martial arts, psychotherapy, and much more. Techniques of improvisation are widely used in training for performing arts or entertainment; for example, music, theatre and dance. Musical improvisation is usually defined as the composition of music while simultaneously singing or playing an instrument. Improvisational comedy is a theater art performed throughout the world and has had on-again, off-again status throughout history. Dance improvisation as a choreographic tool. Improvisation was originally rarely used on dramatic television. A major exception was the situation comedy Mork and Mindy where star Robin Williams, famed for this kind of performing, was allotted specific sections in each episode where he was allowed to perform freely. Improvisation also exists outside the arts. Improvisation in engineering is to solve a problem with the tools and materials immediately at hand. Improvised weapons are often used by guerrillas, insurgents and criminals.